1. Technical Field
The present disclosure relates to surgical stapling apparatus and, more particularly to staple-gap adjustment members for use in surgical stapling apparatus.
2. Background of Related Art
Surgical devices wherein tissue is first grasped or clamped between opposing jaw structures and then joined by means of surgical fasteners are well known in the art. In some such instruments a knife is provided to cut the tissue which has been joined by the fasteners. The fasteners are typically in the form of surgical staples however, other surgical fasteners may also be utilized, such as, for example, clips or two part polymeric surgical fasteners.
Instruments for applying surgical fasteners typically include two elongated beam members which are respectively used to capture or clamp tissue therebetween. Typically, one of the beam members carries a disposable cartridge which houses a plurality of staples arranged in at least two lateral rows while the other beam member comprises an anvil which defines a surface for forming the staple legs as the staples are driven from the cartridge. Where two part fasteners are used, this beam member carries the mating part, e.g. the receiver, to the fasteners driven from the cartridge. Generally, the staple formation process is effected by the interaction between a longitudinally moving camming surface and a series of individual staple pusher members. As the camming surface travels longitudinally through the cartridge carrying member, the individual pusher members are biased laterally, thus acting upon the staples to individual pusher members are biased laterally, thus acting upon the staples to sequentially eject them from the cartridge. A knife may travel with the pusher between the staple rows to longitudinally cut the tissue between the rows of formed staples. Examples of such instruments are disclosed in U.S. Pat. Nos. 3,079,606 and 3,490,675.
A later stapler disclosed in U.S. Pat. No. 3,499,591 applies a double row of staples on each side of the incision. This is accomplished by providing a cartridge assembly in which a cam member moves through an elongate guide path between two sets of staggered staple carrying grooves. Staple drive members are located within the grooves and are positioned in such a manner so as to be contacted by the longitudinally moving cam to effect ejection of the staples.
It is desired and it is a main objective of the present disclosure to provide improved surgical fastener applying apparatus, and to provide improved mechanisms and methods for producing improved surgical fastener applying apparatus, which apparatus have a uniform fixed staple gap that is consistently within a narrow range, well within the acceptable staple gap tolerance range, and that consistently produces formed staples that are within a narrow range well within the acceptable staple tolerance range.
Accordingly, the need exists for surgical fastener applying apparatus which has a uniform fixed staple gap that is consistently within a narrow range and that will remain uniform during a firing stroke. In addition, the need exists for a surgical fastener applying apparatus which will not fire if a disposable staple cartridge is not properly loaded within the apparatus or is not loaded in the apparatus at all or will not fire if the surgical fastener applying apparatus is in an unclamped state. The continuing need exists for a surgical fastener applying apparatus which will not accept a completely fired or a partially fired disposable staple cartridge therein.